PROJECT SUMMARY/ABSTRACT In response to PA-15-261: The Health of Sexual and Gender Minority Populations, this project ?Health, Stress, and Tobacco Use Disparities among Sexual Minority Populations? proposes to use an existing nationally representative dataset to assess the relationships among sexual orientation, discrimination, stress, tobacco/nicotine use behaviors, and DSM-5 tobacco use disorder in the U.S. Tobacco use remains the leading preventable cause of death; cigarette smoking is responsible for more than 480,000 deaths per year in the U.S. Past research has generally found sexual minorities are at heightened risk for cigarette smoking and other tobacco/nicotine use. However, many of these studies are plagued by methodological limitations including small, non-representative samples, lack of heterosexual comparison groups and/or limited sexual orientation measures. To date, no nationally representative studies have examined the DSM-5 tobacco use disorder disparities among sexual minorities and few data exists on severity, comorbidity, disability, help seeking, and recovery associated with DSM-5 tobacco use disorder among sexual minorities. Thus, we propose to build on our prior work and conduct secondary analyses of the 2012-2013 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC-III), a nationally representative survey of 36,309 U.S. adults 18 years and older in the U.S. The NESARC-III study represents the only nationally representative study that has sufficient measures and sample size to test for potential age, gender, racial/ethnic, and socioeconomic status differences and to meet the objectives of our study, which aims to: (1) examine the prevalence of (a) cigarette smoking, e-cigarette use, and other tobacco/nicotine use, (b) DSM-5 tobacco use disorder severity (includes tobacco and/or nicotine products), and (c) comorbidity of DSM-5 tobacco use disorder and mental health disorders based on major dimensions of sexual orientation (attraction, behavior, and identity); (2) assess the disability (e.g., general health, physical functioning, and social functioning), help seeking (e.g., counseling, nicotine replacement therapy, and medication), and recovery (e.g., early and sustained remission) associated with tobacco/nicotine use and DSM-5 tobacco use disorder based on sexual orientation; and (3) determine the relationships among stressful events, sexual orientation discrimination (individual-level and institutional-level), tobacco/nicotine use and DSM-5 tobacco use disorder based on the Comprehensive Developmental and Minority Stress Model. This project will take advantage of the unique opportunities afforded by the 2012-2013 NESARC-III: the availability of an ethnically / racially diverse sample with large numbers of sexual minorities; the inclusion of multiple measures of sexual orientation based on attraction, behavior and identity; and the wealth of data on cigarette smoking, other tobacco/nicotine use, DSM-5 tobacco use disorder, and DSM-5 mental health disorders. Measures of stressful life events and sexual orientation discrimination will enable assessment of two of the major factors presumed to account for health disparities among sexual minorities.